1/*$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 tkusumi Exp $*/
2
3/*
4 * Copyright (c) 2009 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Adam Hamsik.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD: dm_target_mirror.c,v 1.24 2020/01/21 16:27:53 tkusumi Exp $");
33
34/*
35 * This file implements initial version of device-mapper mirror target.
36 */
37#include <sys/types.h>
38#include <sys/param.h>
39#include <sys/buf.h>
40
41#include "dm.h"
42
43/* dm_target_mirror.c */
44int dm_target_mirror_init(dm_table_entry_t *, int, char **);
45char *dm_target_mirror_table(void *);
46int dm_target_mirror_strategy(dm_table_entry_t *, struct buf *);
47int dm_target_mirror_sync(dm_table_entry_t *);
48int dm_target_mirror_destroy(dm_table_entry_t *);
49//int dm_target_mirror_upcall(dm_table_entry_t *, struct buf *);
50
51typedef struct target_mirror_config {
52#define MAX_MIRROR_COPIES 4
53	dm_pdev_t *orig;
54	dm_pdev_t *copies[MAX_MIRROR_COPIES];
55
56	/* copied blocks bitmaps administration etc*/
57	dm_pdev_t *log_pdev;	/* for administration */
58	uint64_t log_regionsize;	/* blocksize of mirror */
59
60	/* list of parts that still need copied etc.; run length encoded? */
61} dm_target_mirror_config_t;
62
63#ifdef DM_TARGET_MODULE
64/*
65 * Every target can be compiled directly to dm driver or as a
66 * separate module this part of target is used for loading targets
67 * to dm driver.
68 * Target can be unloaded from kernel only if there are no users of
69 * it e.g. there are no devices which uses that target.
70 */
71#include <sys/kernel.h>
72#include <sys/module.h>
73
74MODULE(MODULE_CLASS_MISC, dm_target_mirror, "dm");
75
76static int
77dm_target_mirror_modcmd(modcmd_t cmd, void *arg)
78{
79	dm_target_t *dmt;
80	int r;
81
82	switch (cmd) {
83	case MODULE_CMD_INIT:
84		if ((dmt = dm_target_lookup("mirror")) != NULL) {
85			dm_target_unbusy(dmt);
86			return EEXIST;
87		}
88		dmt = dm_target_alloc("mirror");
89
90		dmt->version[0] = 1;
91		dmt->version[1] = 0;
92		dmt->version[2] = 0;
93		dmt->init = &dm_target_mirror_init;
94		dmt->table = &dm_target_mirror_table;
95		dmt->strategy = &dm_target_mirror_strategy;
96		dmt->sync = &dm_target_mirror_sync;
97		dmt->destroy = &dm_target_mirror_destroy;
98		//dmt->upcall = &dm_target_mirror_upcall;
99
100		r = dm_target_insert(dmt);
101
102		break;
103
104	case MODULE_CMD_FINI:
105		r = dm_target_rem("mirror");
106		break;
107
108	case MODULE_CMD_STAT:
109		return ENOTTY;
110
111	default:
112		return ENOTTY;
113	}
114
115	return r;
116}
117#endif
118
119/*
120 * Init function called from dm_table_load_ioctl.
121 * start length mirror log_type #logargs logarg1 ... logargN #devs device1 offset1 ... deviceN offsetN
122 * 0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0 253:4 0 253:5 0
123 */
124int
125dm_target_mirror_init(dm_table_entry_t *table_en, int argc, char **argv)
126{
127
128	printf("Mirror target init function called!!\n");
129
130	table_en->target_config = NULL;
131
132	return ENOSYS;
133}
134
135/* Table routine called to get params string. */
136char *
137dm_target_mirror_table(void *target_config)
138{
139
140	return NULL;
141}
142
143/* Strategy routine called from dm_strategy. */
144int
145dm_target_mirror_strategy(dm_table_entry_t *table_en, struct buf *bp)
146{
147
148	bp->b_error = EIO;
149	bp->b_resid = 0;
150
151	biodone(bp);
152
153	return 0;
154}
155
156/* Sync underlying disk caches. */
157int
158dm_target_mirror_sync(dm_table_entry_t *table_en)
159{
160
161	return 0;
162}
163
164/* Doesn't do anything here. */
165int
166dm_target_mirror_destroy(dm_table_entry_t *table_en)
167{
168
169	/* Unbusy target so we can unload it */
170	dm_target_unbusy(table_en->target);
171
172	return 0;
173}
174
175#if 0
176/* Unsupported for this target. */
177int
178dm_target_mirror_upcall(dm_table_entry_t *table_en, struct buf *bp)
179{
180
181	return 0;
182}
183#endif
184